Well first of all an "ideal anime" doesn't exist. Hopefully in the future someone will come to there senses and not mess up there work. For me though an ideal anime would be an anime that...

1. Makes sense, explains character situation and how he got his powers. (if he has any)

2. Full bound romance. Not some cheesed up last episode kiss scene. I'm talking start dating and continue relationship through the anime until the end.

3. Main character with some sort of swag and not so many character that look so ridiculously stupid and piss you off every time they pop up in a scene .

4. Very few mini-episodes. THEY PISS ME OFF! Your going ahead enjoying the arc and then boom you just waited for a new episode to come out and it was a completely useless. (Naruto is good example of this, no offense)

5. No twisted and utterly idiotic plots or something super predictable. Keep it enjoyable for the audience and try not to piss them off with some crazy plot change that makes no sense what so ever.

the wide cast of interesting characters like Baccano!/Durarara!
the mysterious deaths of Another
a hero like Emiya Kiritsugu or Light Yagami
a girl like Rin Asogi who constantly gets killed, again and again
a metal soundtrack
a complete lack of romance
twists, twists and more twists
and Jojo's voice actors

Something like Code Geass or Gundam 00 where there's a lot of politics intertwined with the plot and a terrorist organization fighting the government. Also, good character story lines with deep, interesting backgrounds.